Improvement in amalgamating gold and silver



UNITED STATES PATENT ()FFICEO A. K. EATON, OF NENV YORK, N. Y.

IMPROVEMENT IN AMALGAMATING GOLD AND S ILVER.

Specification forming part of Letters Patent No. 10,734, dated April 4, 1854.

To all whom it may concern.-

Be it known that I, A. K. EATON, of the city, county, and State of New York, have invented certain new and useful Improvements in the Process of Separating Precious Metals from their Ores by Amalgamation and Washing, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form part of this specification,and in which- Figure 1 represents a top view, and Fig. 2 a longitudinal section, of an amalgamating trough.

In the process of extracting the precious metals from ores it is usual, first, to roast the ores to reduce the sulphurets and expel the sulphur, next to grind the roasted ores, and then to stir the finely pulverized ore among mercury, or bring it in contact with the mercury, that the latter by virtue of its strong afiinity for the precious metals may attract or absorb them from the earthy matter. During the operation of stirring theore and mercury together, a considerable quantity of the latter is reduced to a state of fine division, and these finely-comminuted particles float off on the surface of the water with which the earth is washed out, and thus a great loss results. Moreover, numerous fine particles of the precious metal are floated off in the same manner and lost.

It is the chief object of my present in vention to prevent the before mentioned loss, both of the mercury and precious metal; and it consists in maintaining Ia bright metallic surface of the mercury employed,and increasing its affinity for the precious metals by al loying it with a small portion of zincsay, from one to ten per cent.,according to the quantity ofsulphnr present in the ore; the sulphuration of the mercury is by this means prevented, as the affinity of zinc for sulphur is much stronger than thatof mercury; and my invention further consists in causing all the water with which theme is washed to flow as it escapes in contact with amalgamated bars, plates, or other surfaces of amalgamated zinc, which will collect all the fine particles, both of the mercury and precious metals,and thus prevent waste.

As the method of forming an amalgam of zinc and mercury is well known, it is unnecessary here to describe it further than to say that the quantity of zinc used must be suflicient to protect the mercury from sulphuration.

As the same ore when roasted well will contain far less sulphur than when badly roasted, the quantity of zinc to be used cannot be reduced to any exact rule. It is, however, desirable to do with the least possible quantity when the amalgam is mixed in mass with the ore, as the zinc very rapidly destroys the fluidity ofthe mercury; but in case the amalgam is not to be used in the ordinary way by mixing it with the ore, but instead is to be used to collect fine particles of floating metal, then the preservation of the fluidity of the amalgum is not of so much importance,and it may be formed in a convenient and suitable manner by applying mercury to the surface of a A represents a trough to convey the water off.

Across this trough aseries of inclined bars, I), of amalgamated zinc are placed. in such a manner that the water as it passes through the through will have to run in contact with them.

A second plan would be to place perforated diaphragms c of amalgamated zinc across the trough through which the water would 'be compelled to run in numerous fine streams, and would of course be brought in contact with a large aggregate surface of the amalgamated metal, as illustrated in Fig. 3.

Another method would be to place a funnelshaped diaphragm, d, perforated with numerous small holes round its sidesin such position that the water would run thr0ugh,and in so running the numerous vortexes that will be produced will cause the water to pass in contact with so large an amount of the amalgamated surface that it would be exceedingly difficult for it to bear off a particle either of Washed, by means of surfaces of amalgamated mercury or gold. This modification is shown zinc, in contact with which the water is caused in Fig. 4. to flow as it escapes, substantially as herein What I claim as my invention, and desire to set forth.

secure by Letters Patent, is In testimony whereof I have hereunto subl. The employment of an alloy of mercury scribed my name.

and zinc, instead of pure mercury,in the process of amalgamating precious metals.

2. The method of colleetingthe fine par- VVitnesses:

tieles of mercury and precious metal that float P. H. WATSON,

off in the water with which the amalgam is PETER HANNAY.

A. K. EATON. 

